1. Field of the Invention
This invention relates to a support for photographic use which has a subbing layer thereon, and more particularly to a polyester support for photographic use to which a subbing process is applied by coating thereon with a particular aqueous copolymer composition with the purpose of tightly adhering thereon such a hydrophilic colloidal layer as a light-sensitive emulsion layer, a backing layer or the like.
2. The State of the Prior Art
Polyester films are excellent in physical properties to serve as the supports of silver halide photographic light-sensitive materials and the like, and accordingly there is a great demand for this article and a wide use thereof in recent years. Such polyester films are sometimes attended with difficulties to adhere to a support like the above with a hydrophilic colloidal layer such as a photographic gelatin layer using a binder such as gelatin, because such polyester films are hydrophobic. Heretofore, there have been known many subbing processes in the photographic light-sensitive materials having used polyester films to make the support adhere to the hydrophilic colloidal layers. There have however been many instances, in any of the above subbing processes, where swelling agents or dissolving agents for polyester films should have been used to make tightly adhere such hydrophilic colloidal layers and inter alia photographic gelatin layer to the supports. In the case, however, that a subbing composition containing such a swelling agent or dissoloing agent should have been coated on a polyester film, there have been many defects such as an impediment of safety and hygiene in work operations and the like, because the flatness of the support has been worsened in the course of subbing treatment or most of the swelling agents or dissolving agents have used harmful organic solvents. Therefore, there have been proposed the subbing treatment without using any swelling agent or dissolving agent.
In one of the subbing techniques, there has proposed a polyester film whose surface is treated chemically or physically to serve as a support applied with such a surface activation treatment as a chemical treatment, a mechanical treatment, a corona discharge treatment, a flame treatment, an ultraviolet ray treatment, a high-frequency treatment, a glow discharge treatment, an active plasma treatment, a laser treatment, a mixed acid treatment, an ozone-oxidation treatment and the like. This technique has been proposed in U.S. Pat. Nos. 2,943,937, 3,475,193, 3,615,557, and 3,590,107; British Patent No. 1,215,234; and Japanese Patent Publication Open to Public Inspection (hereinafter called Japanese Patent O.P.I. Publication) Nos. 13672/1978 and 18469/1980, respectively. These surface-treated polyester films have been unsatisfactory in adhesion strength while the adhesion thereof to a hydrophilic protective colloidal layer for photographic use has increased.
In addition to the above, with the purpose of increasing the adhesion thereof to a hydrophilic colloidal layer for photographic use, there has proposed a polyester film to which an aqueous coating composition layer has been provided after a surface treatment was applied to the surface of the film. This type of aqueous coating composition layer, i.e., a subbing layer, is required to be satisfactorily adhesive to both of the polyester film and the hydrophilic colloidal layer for photographic use. In particular, with the purpose of making a subbing layer adhere satisfactorily to a hydrophilic colloidal layer, a hydrophilic group or a reactive group is popularly included in the components of resin (hereinafter called a subbing resin) in a subbing layer. As such hydrophilic groups or reactive groups as mentioned above, there may be given, for example, such an acid as acrylic acid, itaconic acid, a semialkyl ester of itaconic acid and the like; an N-alkanol group such as N-methylol acrylamide, hydroxymethylated N-(1,1-dimethyl-3-oxobutyl) acrylamide and the like; a hydroxyl group such as hydroxyethyl methacrylate, hydroxyethyl acrylate and the like; an epoxy group such as glycidyl acrylate, glycidyl methacrylate and the like; and the like.
Among the above described, the examples of such subbing layers containing subbing resins containing acid components have been disclosed in Japanese Patent Examined Publication No. 3564/1973; Japanese Patent O.P.I. Publication Nos. 1123/1971, 1718/1975, 61518/1979, and 39536/1975; European Patent Publication No. 1484; U.S. Pat. No. 3,545,972; and the like. However, in a polyester film bearing thereon a subbing layer containing an acid component within the subbing resins of the subbing layer, the adhesion strength of the hydrophilic protective colloidal layer has been unsatisfactory when developing.
The examples of subbing layers each containing subbing resins containing N-alkanol group components have been respectively disclosed in French Pat. No. 140,408, Japanese Patent O.P.I. Publication No. 131516/1976, British Pat. No. 1,178,591, Japanese Patent Examined Publication No. 3054/1982 and the like. These types of N-alkanol acrylamide disclosed in the above patents were serious in self-bridged bonding property to cause a bridged bond in the course of synthesizing subbing resins or during the preservation of a synthetic solution, so that the stability of such synthetic solutions and subbing solutions were not satisfactory.
The examples of subbing layers each containing subbing resins containing hydroxyl group components have been disclosed in Japanese Patent O.P.I. Publication Nos. 69138/1980, 19786/1977, 135526/1976, 123139/1976, 113868/1974 and the like.
In was however difficult to stably perform any subbing treatment with the subbing resins disclosed in the above-mentioned patents, because the synthetic solution of the subbing resins or the aqueous composition containing the subbing resins, each of which is a processed solution for subbing use (hereinafter called a "subbing solution"), is apt to be chemically degenerated or mechanically instable.
The examples of subbing layers each containing subbing resins containing epoxy group components have been disclosed in Japanese Patent O.P.I. Publication Nos. 9629/1959, 58469/1976, 104913/1977, 27918/1976, 19786/1977, 30121/1979, 121323/1976 and 69138/1980; and British Pat. No. 1,168,171; and the like.
It was however impossible to stably perform any constant subbing treatment, because the adhesion of the subbing solution containing the described subbing components was instable.
As mentioned above, with the polyester films for photographic use each having the subbing layer containing the subbing resins containing a hydrophilic group or a reactive group, the stability of the polyester films and the subbing capability thereof were not always satisfactory at the time of manufacture.